446 research outputs found
Projects, participation and planning across boundaries in Göttingen
This paper explores efforts to coordinate strategies promoting sustainable development – with specific focus on mobility and transport in climate change mitigation – across administrative boundaries in the city and county of Göttingen, Germany. The paper questions the possibility to develop and align strategic objectives and implementation across administrative boundaries when relying on short-term project funds. The experiences of key stakeholders in Göttingen are presented, with reference to empirical data from a document and interview study. Results indicate that reliance on short-term, project-based funding from external sources offers both opportunities and challenges for locally and regionally integrated strategy formulation and implementation. Five factors shaping the strategy space of actors are used to frame the analysis, with findings suggesting the need for further research on how local authorities overcome capacity and resource limitations, particularly with respect to complex challenges such as climate change
Prognostic impact of urokinase-type plasminogen activator (uPA) and its inhibitor (PAI-1) in cytosols and pellet extracts derived from 892 breast cancer patients
To evaluate the clinical relevance of urokinase-type plasminogen activator (uPA) and its type-1 inhibitor (PAI-1) measured by a recently developed enzyme-linked immunosorbent assay (ELISA), we analysed both components in samples derived from 892 patients with primary breast cancer (median follow-up 99 months). The assays were performed in cytosolic extracts as well as in corresponding detergent extracts of pellets obtained after ultracentrifugation, which was carried out when preparing the cytosolic fractions for routine steroid hormone receptor determination. Statistically significant correlations were found between the cytosolic levels and those determined in the pellet extracts (Spearman correlation coefficient rs = 0.60, P < 0.0001 for uPA and rs = 0.65, P < 0.0001 for PAI-1). Furthermore, strong correlations were found between the levels of both uPA (rs = 0.85, P < 0.0001) and PAI-1 (rs = 0.90, P < 0.0001) in the cytosols and their levels previously measured with ELISAs based on commercial reagents. In both Cox univariate and multivariate analysis, high cytosolic levels of uPA or PAI-1 were significantly associated with increased rates of relapse and death. The levels of uPA and PAI-1 in the pellet extracts also provided prognostic information, although to a lesser extent compared with the cytosolic extracts. The prediction of prognosis on the basis of uPA and PAI-1 assessed by an alternative ELISA once again emphasizes the established prognostic role and usefulness of these parameters in selection of breast cancer patients at high or low risk of recurrence. © 1999 Cancer Research Campaig
Risk-group discrimination in node-negative breast cancer using invasion and proliferation markers: 6-year median follow-up
Local Causal States and Discrete Coherent Structures
Coherent structures form spontaneously in nonlinear spatiotemporal systems
and are found at all spatial scales in natural phenomena from laboratory
hydrodynamic flows and chemical reactions to ocean, atmosphere, and planetary
climate dynamics. Phenomenologically, they appear as key components that
organize the macroscopic behaviors in such systems. Despite a century of
effort, they have eluded rigorous analysis and empirical prediction, with
progress being made only recently. As a step in this, we present a formal
theory of coherent structures in fully-discrete dynamical field theories. It
builds on the notion of structure introduced by computational mechanics,
generalizing it to a local spatiotemporal setting. The analysis' main tool
employs the \localstates, which are used to uncover a system's hidden
spatiotemporal symmetries and which identify coherent structures as
spatially-localized deviations from those symmetries. The approach is
behavior-driven in the sense that it does not rely on directly analyzing
spatiotemporal equations of motion, rather it considers only the spatiotemporal
fields a system generates. As such, it offers an unsupervised approach to
discover and describe coherent structures. We illustrate the approach by
analyzing coherent structures generated by elementary cellular automata,
comparing the results with an earlier, dynamic-invariant-set approach that
decomposes fields into domains, particles, and particle interactions.Comment: 27 pages, 10 figures;
http://csc.ucdavis.edu/~cmg/compmech/pubs/dcs.ht
Accumulation of uPA – PAI-1 complexes inside the tumour cells is associated with axillary nodal invasion in progesterone-receptor-positive early breast cancer
External quality assessment of trans-European multicentre antigen determinations (enzyme-linked immunosorbent assay) of urokinase-type plasminogen activator (uPA) and its type 1 inhibitor (PAI-1) in human breast cancer tissue extracts.
High levels of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) in breast cancer tissue extracts have been associated with rapid disease progression. In these studies, different enzyme-linked immunosorbent assay (ELISA) kits have been applied for the quantification, and consequently the ranges of uPA and PAI-1 levels reported differ considerably. Therefore, the Receptor and Biomarker Study Group (RBSG) of the European Organization for Research and Treatment of Cancer (EORTC) and a consortium of the BIOMED-1 project 'Clinical Relevance of Proteases in Tumor Invasion and Metastasis' initiated three collaborative between-laboratory assessment trials aimed at controlling uPA and PAI-1 antigen analyses. For this purpose, two control preparations were produced from different sources: pooled human breast cancer specimens (QC-240893) and human breast cancer xenografts raised in nude mice (QC-101094). The lyophilized preparations were stable for prolonged times (at least 3 and 27 months respectively) at 4 degrees C. Furthermore, a good parallelism following dilution was found for uPA and PAI-1. The data from QC trial no. 1 clearly indicated that acceptable between-laboratory coefficients of variation (CVs) for uPA (<8.2%) and PAI-1 (<16.6%) in QC-240893 could be achieved when the same type of ELISA kit (American Diagnostica) was used. From the second trial, in which ten EORTC laboratories each received five identical lyophilized QC-101094 samples, it appeared that the within-laboratory variations for uPA and PAI-1 determinations obtained by 'experienced' laboratories were lower (<12.9%) than those from non-experienced laboratories (<36.4%). In a third QC trial, five BIOMED-1 laboratories, all of which employed ELISA procedures for uPA and PAI-1, participated in six subsequent quality assessment rounds receiving five samples of QC-101094. Although for each laboratory the within-run CVs for uPA as well as for PAI-1 were low (<7.8%), the between-run CVs were found to be considerably higher (up to 56.2% for uPA and to 27.6% for PAI-1). Consequently, because of the different ELISA formats used, the absolute analyte values measured in the different laboratories varied substantially. The use of 'common external standards' in the different ELISAs resulted in a significant reduction of the between-laboratory CVs from 61.3% to 15.7% (uPA) and from 42.1% to 19.1% (PAI-1). The present data demonstrate that in multicentre studies the same ELISA kit should be used, and that external quality assurance (QA) is mandatory. Furthermore, it appears from the present study that standardization of the protein assay as a tissular parameter is imperative
Prognostic value of tissue-type plasminogen activator (tPA) and its complex with the type-1 inhibitor (PAI-1) in breast cancer
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